The present invention relates to a storage device carrying the security function and a host apparatus to which the storage device is connectable and more particularly, to a memory card having a flash memory chip as a storage medium and to a cellular phone and a PDA (personal digital assistant) to which the memory card is connectable.
Nowadays, many providers are marketing small-sized memory cards of various standards. In general, the small-sized memory card has a memory capacity of several of mega to several of giga and it is connected to or inserted into a portable terminal, camera, AV (audio and visual) apparatus or information terminal so as to be used for storage and distribution of data and reception/transfer of data between apparatus.
Internally, the small-sized memory card has an interface connectable with external apparatus in a wireless/wired fashion, a non-volatile rewritable memory and a single or a plurality of controllers for controlling the former two and is fed with an external power supply, so that it can afford to perform operations such as read, write and erase of data.
As one of small-sized memory cards of this type, a secure MMC (multiMediaCard) is available. It should be understood that “Multimedia card” is a registered trademark by Infineon Corp. The secure MMC has a function to verify a certificate of the other party of communication in order to read private data out of a memory, different from an ordinary memory and dedicated to storage of private data, and transmit the read-out private data to only a legal or authorized communication partner.